The present invention relates to an applanation tonometer with a measuring body capable to be put against the eye and with means for automatically detecting the pressure force of the measuring body as well as the applanation surface caused by said pressure force and for calculating the intraocular pressure from the measured quantities. Such a tonometer is known e.g. from W087/01572. This one and generally all known applanation tonometers are so designed that they have to be operated by a corresponding instructed personal, more particularly by a doctor, in order to measure the eye pressure of the person experimented upon, i.e., the patient. Also when the proper measuring process is largely automatized and takes place electronically the handling with the tonometer is difficult if the measurement is to be correct and must take place without any danger of injury. New trends admit however that the intraocular pressure should be checked with regularity and relatively often, wherein it is important or necessary to detect the evolution of the pressure during one day. However, such a desired measurement executed at relatively shorts intervals of time is connected to insupportable expenses if not only the person experimented upon, resp. the patient but also an instructed auxiliary person has to participate.